The present invention relates to an improved autosteering system, and more particularly relates to improvements in an auto-steering system for navigation in which a known feedback control circuit automatic controls rudder angles in accordance with signals from a known sensor circuit.
In auto-steering systems for navigation, the condition of various environmental factors influencing navigation such as navigation course, wind heading and/or tideway are sensed by a sensor circuit which produces corresponding signals. These signals are accepted by a control circuit which automatically controls the rudder angle using a feedback control. In order to carry out this control operation, the control circuit must be retained in approximately the zero-condition when the control circuit is inoperative. If this condition is not met, the rudder control can malfunction since turning of the rudder is carried out relative to the standard rudder angle position which is deviated from the true zero-point position, i.e. the neutral axis coinciding the stern direction of the boat equipped with the auto-steering system. As a result of this disorder in the rudder control operation, it is quite impossible, when any malfunction occurs in the system, to confirm whether the system malfunction is caused by any disorder or disorders in the rudder mechanism and/or the sensor circuit or the system malfunction is caused by absence of the zero-point calibration of the control circuit.